Yups, for an hour ago, my YM account cannot display any chat from my friend, and whe i type it and send it to my message, the message just show a blank white.
To resolve this just follow the instruction bellow :
Open a registry editor (click Start, click Run. On the Open box, type: regedit and then press Enter). Navigate to the following key: HKEY_CURRENT_USER \ Software \ Microsoft\ Windows \ CurrentVersion \ Internet Settings \ Zones
There should only be 5 items there, numbered 0 to 4. At my registry, it will be display "L" key value. If you see a different one, especially if you see items that shows up as box, try deleting it. (Backup your registry first). If you were able to delete that extra item, this might fix the bug, and you will be able to see the chat messages again in yahoo messenger."
I have try it my self and it Works !! :)
hope this works for someone else!
Reference : BigBlueBall